Referring to FIGS. 1 and 2, a conventional blade holding device 1 for holding a saw blade 2 includes a clamp member 11, a sleeve ring 12, a shell 13, two fixing members 14, and two fastening members 15. The clamp member 11 has two spaced-apart half portions 111 defining a gap 110 therebetween, and two spaced-apart threaded holes 112 extending through one of the half portions 111 and communicating spatially with the gap 110. The gap 110 is for receiving the saw blade 2. The sleeve ring 12 is sleeved on an end part of the half portions 111 of the clamp member 11 (see FIG. 2). The shell 13 has a shell body 131 surrounding the sleeve ring 12 and the clamp member 11, and being formed with an opening 132 to expose the threaded holes 112. The fixing members 14 extend through the shell 13 and threadedly engage the clamp member 11 so that the shell 13 is secured to the clamp member 11. The fastening members 15 extend through the opening 132, and respectively and threadedly extend through the threaded holes 112 to press against the saw blade 2 for securing the saw blade 2.
The conventional blade holding device 1 has the following drawbacks:
1. Since the sleeve ring 12 is sleeved on only the end part of the half portions 111 of the clamp member 11, when a user uses the back of the saw blade 2 to hit a hard object (not shown), the sleeve ring 12 may not be able to provide sufficient coupling strength, and the sleeve ring 12 and the shell 13 may be easily damaged.
2. The saw blade 2 may need to be replaced frequently. Threads of the threaded holes 112 of the clamp member 11 may be worn due to repeated screwing and unscrewing of the fastening members 15 for replacing the saw blade 2. As such, the fastening members 15 and the clamp member 11 may fail to hold the saw blade 2 securely.
3. The shell 13 and the clamp member 11 are secured to each other only by the fixing members 14, when the saw blade 2 reciprocates at a relatively high speed during operation, the shell 13 may slide out from the clamp member 11 when the restriction imposed by the fixing members 14 is overcome or when the fixing members 14 is broken.